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| author | David Vrabel <david.vrabel@citrix.com> | 2011-09-28 17:46:33 +0100 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2011-09-29 11:12:09 -0400 |
| commit | b1cbf9b1d6af22ba262d99abcfd71d5d90dbd57a (patch) | |
| tree | ff8a5c8d68451f5ef23bc427351e061ef42ae7a4 /drivers/xen | |
| parent | aa24411b6717fd1e6ecef281bec497f6f30bbd66 (diff) | |
| download | lwn-b1cbf9b1d6af22ba262d99abcfd71d5d90dbd57a.tar.gz lwn-b1cbf9b1d6af22ba262d99abcfd71d5d90dbd57a.zip | |
xen/balloon: simplify test for the end of usable RAM
When initializing the balloon only max_pfn needs to be checked
(max_pfn will always be <= e820_end_of_ram_pfn()) and improve the
confusing comment.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/balloon.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 4f59fb373381..9efb993090aa 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -586,16 +586,16 @@ static int __init balloon_init(void) #endif /* - * Initialise the balloon with excess memory space. We need - * to make sure we don't add memory which doesn't exist or - * logically exist. The E820 map can be trimmed to be smaller - * than the amount of physical memory due to the mem= command - * line parameter. And if this is a 32-bit non-HIGHMEM kernel - * on a system with memory which requires highmem to access, - * don't try to use it. + * Initialize the balloon with pages from the extra memory + * region (see arch/x86/xen/setup.c). + * + * If the amount of usable memory has been limited (e.g., with + * the 'mem' command line parameter), don't add pages beyond + * this limit. */ - extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()), - (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size)); + extra_pfn_end = min(max_pfn, + (unsigned long)PFN_DOWN(xen_extra_mem_start + + xen_extra_mem_size)); for (pfn = PFN_UP(xen_extra_mem_start); pfn < extra_pfn_end; pfn++) { |